1. The Field of the Invention
The present invention relates to reduced-size antennas and the manufacturing thereof. More particularly, the present invention relates to the structure and fabrication of thin-profile, compact antenna configurations.
2. The Background of the Invention
Antenna structures have long manifest themselves as large protuberances and often as extendable metallic projections from the electronic equipment which they service. Antennas, while essential for transmitting and receiving electromagnetic propagable electromagnetic waves, have been both cumbersome and aesthetically undesirable. While it is essential for effective antenna configurations to assume a dimension proportional to the wavelength of the carrier signal, very little advancements have taken place in attending to the minimization of the generally obnoxious nature of antenna structures on portable equipments.
With the advancements of spectrum allocations in higher frequency ranges, antenna structures have benefited from the reduced wavelength of such high frequency signals. That is to say, as electronic devices employ higher frequency spectrums, the associated wavelength, which dictates the effective length of antenna structures, decreases. Therefore, smaller form-factor devices such as wireless telephones, portable transceivers such as those on computing electronics, are capable of assuming desirable integral integrated and miniaturized configurations.
In order to facilitate the integration of antennas into reduced-size electronics, electronics designers have largely resorted to merely placing an otherwise external structure at least partially within the housing confines of the electronic equipment. While such xe2x80x9cintegrationxe2x80x9d results in less obtrusive antenna-laden equipment, such advances have not generally attempted to address the manufacturing and structural needs for an ever increasing trend toward integration and miniaturization of electronics.
Another approach for reducing the obvious nature of antenna structures has been to fabricate the radiating elements of antenna structures onto printed circuit boards and integrate those printed circuit boards into the housing of the electronic device. The effectiveness of such planer-structure antenna elements suffer from the directional nature of planer antennas, that is to say, the orientation imposed upon the electronic equipment by the manipulation of a user or otherwise, effects the gain or capability of the antenna. Furthermore, electronic circuitry adjacent to the planer radiating element of the antenna induces interference and further effects the antenna""s gain profile. Therefore, it is desirable to create a planer antenna structure that is extendable from interfering electronics. Furthermore, it would be a further advancement in the art to provide an antenna structure and a method for manufacturing an antenna structure that enables a thin-profile planer antenna to be extendable from interfering electronics, thereby presenting an improved gain profile of the antenna while maintaining structural and aesthetic integrity of the electronic product in a miniaturized form-factor environment.
It is an object of the present invention to provide a housing for enclosure of thin-profile planer electronic devices that would otherwise lose their desirable thin dimensions if subjected to traditional enclosure options.
It is another object of the present invention to provide a mechanical stiffner for protecting thin profile planer electronics from exposure.
It is a further object of the present invention to maintain small ergonomic dimensions compatible with integrated miniaturized electronics.
It is yet a further object of the present invention to provide a method for forming an antenna structure from a printed circuit board with a planer radiating element thereon while maintaining the desirable narrow dimensions of the device while still providing a protective housing for enclosing the devices.
An antenna structure for connecting to a transceiver is presented which is comprised of a printed circuit board having first and second sides with distal and proximal ends and a planer electromagnetic radiating element (i.e., the electrical antenna proper). The radiating element, while generally planer, has distal and proximal ends which correspond generally to the distal and proximal ends of the printed circuit board. The proximal end of the printed circuit board provides a connector coupling through cabling such as coaxial cabling to the transceiver which originates transmitting signals and receives signals from the radiating element.
The antenna structure is further comprised of an overmolded sheath which encapsulates both at least a portion of the distal end of the printed circuit board and the distal end of the radiating element affixed thereto. An overmolded sheath is employed for encapsulating the generally planer geometries of the printed circuit board and the radiating element to maintain the generally thin profile of the antenna structure while providing rigidity and protection to the radiating element and printed circuit board. Traditional housing technologies comprised of multiple housing pieces, that undergo subsequent assembly, result in an undesirable and excessive dimension.
Regarding assembly and manufacturing of the overmolded antenna, the overmolded sheath encapsulating the printed circuit board and radiating element is formed, in the preferred embodiment, through an insert injection molding process which allows complete encapsulation of the distal portions of the printed circuit board and radiating element. The overmolded sheath is comprised of flexible plastic, preferably a thermoplastic elastomer, which maintains resilience through moderate flexure of the antenna structure.
These and other objects and features of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter.